This application claims priority of German application No. 199 48 705.7, filed Oct. 9, 1999 and International Application No. PCT/EP00/09796, filed Oct. 6, 2000, the complete disclosure of which is hereby incorporated by reference.
a) Field of the Invention
The invention is directed to a setting out device for tachymeters, comprising a rod which can be set vertically on a target point in the area surrounding a terrain point to be set out, a reflector which is arranged on the rod for tachymetric detection of the target point, and means for communication between the rod and tachymeter.
b) Discussion of the Relevant Art
The use of setting out devices of the type mentioned above for setting out and measuring terrain points together with tachymeters is known in the prior art. However, amid further development of electronic tachymeters, a fast and efficient setting out of terrain points in which projected points in a locality or a terrain are transmitted proceeding from a known position becomes increasingly important.
In order to set out a terrain point, the collimation axis or sighting axis of a tachymeter is brought into a vertical plane which is determined by the vertical direction in the tachymeter position and the direction to the terrain point to be set out. A reflector is oriented in this vertical plane and set up as close as possible to a terrain point to be set out in the area surrounding this terrain point. In the following description, the location where the reflector is set up is referred to as the target point.
The distance to the reflector position is then measured from the tachymeter position and position correction information relating to the target point is obtained from this measured distance with the aid of the known reference position of the terrain point to be set out. On the basis of the position correction information, the terrain point to be set out is manually measured and marked proceeding from the target point.
Particularly in case of great distances between the tachymeter and reflector, the orientation of the reflector and the conversion of position correction information are difficult to carry out because the position correction information is obtained at the tachymeter station, but conversion into the terrain takes place at the target point.
In order to facilitate the transfer of information, it was suggested in JP-A-4-93714 to arrange for wireless data transfer between the tachymeter and a setting out device which is to be set up at the target point and provided with a reflector. For this purpose, the setting out device is provided with a corresponding reception device and a display for showing the transmitted information. However, in the known setting out device, the terrain point to be set out must still be measured manually from the target point. This process is relatively time-consuming when carried out with sufficient accuracy.
Expenditure in time and apparatus for setting out a terrain point increases considerably with increasing demands for accuracy. In practice, a distinction is made between coarse setting out with which an accuracy of about 3 to 10 cm is achieved, medium-accuracy fine setting out with which tolerances of 5 to 10 mm can be achieved, and more accurate fine setting out which allows accuracies of 1 to 3 mm.
In order to transfer a projected point in a locality or a terrain, a coarse setting out is carried out initially, wherein the direction is first predetermined by the tachymeter proceeding from a fixed point. A person carrying the setting out device with the reflector is oriented visually by signaling. Orientation at a distance is carried out in stages by measuring and informing the operator of the setting out device of the distance to be covered. This process is repeated until the target point with the above-mentioned coarse setting out tolerance lies in the area surrounding the terrain point to be set out.
In order to accurately determine the terrain point to be set out, i.e., for fine setting out, the setting out device is held exactly on the target point determined in the coarse setting out. Deviations of the terrain point to be set out from the target point are determined by accurate sighting and measuring with the tachymeter. The values are then initially at the location where the tachymeter is set up. Corresponding position correction information for the terrain point to be set out is then transmitted to the set-up location of the setting out device and measured manually on the ground by the operator, whereupon the located terrain point to be set out is marked. A control measurement is then carried out, if necessary, with the setting out device held at the terrain point to be set out.
Based on this prior art, it is the primary object of the invention to further develop a setting out device of the type described above in such a way that terrain points to be set out can be determined and marked within a short period of time and with great accuracy.
This object is met by a setting out device for tachymeters comprising a rod which can be set vertically on a target point in the area surrounding a terrain point to be set out, a reflector which is arranged on the rod for tachymetric detection of the target point, a transmitting and receiving device for exchanging information with the tachymeter, a computing circuit for determining deviations in position between the target point and terrain point, and an auxiliary setting out device for marking the position of the terrain point to be set out.
The setting out device according to the invention allows an efficient and accurate transmission of the projected points in a terrain because the accuracy of fine setting out can be realized by means of a procedure such as that previously customary for coarse setting out. By identifying in positionally accurate manner the terrain point to be set out, the time-consuming and error-prone manual transmission of position correction information is avoided. In this way, the time required for finding and setting out a projected point in the terrain is considerably reduced without forfeiting accuracy.
In an advantageous construction of the invention, the terrain point to be set out is marked in an optically perceptible manner, for example, by light. This has the advantage that the operator of the setting out device need only arrange a permanent mark at the temporarily identified point to conclude the setting out process.
The auxiliary setting out device preferably has a laser device with a diffractive-optic element for generating a light pattern in the form of a grid, a point field, or in the form of concentric circles. In this way, additional information, for example, concerning the ordering of the terrain point in a point grid, can be gained in addition to the information about the position of the terrain point to be set out.
In a further advantageous construction of the invention, the auxiliary setting out device comprises a laser pointer which is movable in at least two coordinate directions for generating a punctiform mark in the terrain. This embodiment form also allows greater distances between the target point and the terrain point to be set out beyond the conventional tolerances of coarse setting out, so that the orientation in the area surrounding the terrain point to be set out and its determination and marking off can be further accelerated without impairing the above-mentioned accuracy level of an accurate fine setting out.
In an alternative embodiment form, the auxiliary setting out device has a transmitting module arranged at the rod, preferably near the ground, for sending position values, preferably via modulated sound waves and/or electromagnetic waves, and a manually displaceable reception module for receiving the positioning values and for marking the terrain point to be set out. The reception module can be moved by hand like a three-dimensional mouse, wherein its position or reference point identifies the terrain point to be set out. Also, in this case, a terrain point to be set out is determined proceeding from a target point which is at a greater distance from the terrain point than the conventional accuracy range of coarse setting out, so that the entire setting out process can be carried out faster.
The receiver module preferably has an ultrasonic transmitter for locating the terrain point to be set out, for which purpose, a reference point is made to coincide at the receiver module with the imaging of the terrain point to be set out. Further, a device is provided for transferring the spatial position of the reference point of the receiver module to a permanent mark in the terrain. This enables an efficient one-handed operation for positioning and marking off, so that the other hand of an operator remains free for holding the setting out device or the rod with the reflector.
A particularly simple construction and handling of the reception module results when a color pointer is provided at the receiver module for arranging the mark in the terrain, by means of which a permanent color identification can be carried out at the point in the terrain to be set out.
In order to enable advantageous, space-saving transport and storage, the transmitting and receiving unit is coupled to the carrier in a detachable manner. Since this unit generally contains sensitive electronic components, it can be separated from the rod and transported and stored in a specially protected manner. Further, in the case of telescoping rods, this makes possible an arrangement which takes height requirements into account.
In another advantageous construction, a display is provided at the transmitting and receiving device for displaying information, so that not only is the terrain point to be set out marked in the terrain, but the corresponding position correction values can also be adequately detected by the operator at the setting out device. In addition, the display allows communication with the operator at the tachymeter. This is particularly advantageous when the distance between the tachymeter and the setting out device exceeds shouting or hailing distance.
Further, an operator""s control for entering information is provided at the transmitting and receiving unit, so that terrain information to be correlated with a terrain point to be set out can be correlated already during the setting out process. The corresponding information can be transmitted, via the transmitting and receiving unit, to the tachymeter or another evaluating device, so that it is not necessary to correlate subsequently. Further, the operator""s control can also be used for communicating with the operator at the tachymeter.
In another advantageous construction of the invention, the rod has a part on the ground side and a part which can telescope upward, the reflector being arranged at the telescoping part, and the telescoping part is guided in a defined position allocation relative to the ground-side part. In this way, the setting out device can also be used in hard-to-see terrain. In addition, an improved distance measurement accuracy can be achieved at greater measurement distances.
The transmitting and receiving unit is preferably arranged at the ground-side part, so that when the part with the reflector telescopes out, it can always remain easily accessible at the same height for the operator at the setting out device. In order not to impair the accuracy of measurement on one hand and to ensure fast handling of the setting out device on the other hand, means are provided for detecting the position correlation between the telescoping part and the groundside part, so that the change in position of the reflector relative to the target point is taken into account in the determination of position correction information.
To facilitate the coarse orientation, corresponding information is indicated on the display, so that orientation can be carried out quickly even when there is no direct visual contact with the tachymeter from the height of the operator.
For particularly simple orientation of the operator of the setting out device, direction orientation is carried out by means of a position signal which can be switched on and off.
In another advantageous construction, distance instructions can also be carried out via the display for the same reasons. A blinking light with variable blinking frequency is preferably used for this purpose. The blinking frequency is varied depending on whether the distance is too great or too small in relation to the terrain point to be set out. By further varying the blinking frequency, which also includes a constant light or a light that is switched on and off, it can also be indicated that a correct position or reference value is achieved.